My late wife and I had many discussions along this line. I begged her to set something like this up. She even suggested who she might invite to watch me cum. I told her she could do anything with or to me, any where, any time. She pushed my limits many times and I loved every moment. She never agreed to invite anyone to watch. She always said, "I just don't think I could go through it."I'd be quite surprised if any man would not enjoy being jerked off by his wife or GF in front of a group of her friends.
Might just be me, but I'd be up (literally) for that any time!
Like @TravisAW, I think it would be enjoyable as well if it were someone else operating the device, particularly if the SO were part of the audience.